Military assault weapon that projects a stream of blazing oil or gasoline against enemy positions. It consists of one or more fuel tanks, a cylinder of compressed gas to supply the propelling force, and a flexible hose with a trigger-nozzle that ignites and sprays the fuel. Portable flamethrowers are carried on the backs of ground troops; larger units may be installed on tank turrets. Modern flamethrowers, first used in combat in World War I, were used by all major powers in World War II and later wars. They are often used in areas of dense underbrush and against fortified positions at close range.